FIO Protocol (Foundation for Interwallet Operability) is a decentralised, open-source blockchain protocol designed to enhance the usability and efficiency of the existing cryptocurrency ecosystem. Launched in 2020 by the FIO Foundation, the protocol aims to simplify interactions with digital wallets by providing a human-readable address system, thus eliminating the complexity of lengthy alphanumeric public addresses. FIO Protocol integrates seamlessly with existing wallets, exchanges, and crypto payment providers, introducing a standardized method for peer-to-peer and commercial transactions. Its key characteristics include a decentralised mapping of user-friendly FIO Addresses to public blockchain addresses, encrypted metadata capabilities for transactions through FIO Data, and a request-for-payment feature that improves transaction accuracy and security. By streamlining the user experience, FIO Protocol plays a vital role in driving broader cryptocurrency adoption.